View 1和View 2都从父级ContentView获取参数text。但是在View 1中使用@Binding，而View 2使用@State。点击View 1按钮将改变text值。但是，单击后，只有ContentView Text（）更新，但View 2的Text没有更新？为什么会这样呢？
在打印输出中，view 1和view 2都使用新值 “View 1 Text” 调用init。
将View 2更改为使用@Binding将在更新View 2时更新View 2的文本。
下面是示例代码：
ContentView.swift

import SwiftUI

struct ContentView: View {
    @State var showView1: Bool = false
    @State var showView2: Bool = false
    @State var text: String = "Hello World"

    init() {
        print("init ContentView")
    }

    var body: some View {
        VStack {
            Image(systemName: "globe")
                .imageScale(.large)
                .foregroundColor(.accentColor)
            Text("\(text)")

            HStack {
                if showView1 {
                    View1($text)
                }
                if showView2 {
                    View2(text)
                }
            }
            .border(.black)
            HStack {
                Button("View1") { showView1.toggle() }
                Button("View2") { showView2.toggle() }
            }
        }
        .padding()
    }
}

View1.swift

struct View1: View {
    @Binding var text: String
    init(_ text: Binding<String>) {
        self._text = text
        print("init View1  \(self.text)")
    }

    var body: some View {
        Button("Click") {
            print("Click view1 button")
            self.text = "View 1 Text"
        }
    }
}

View2.swift

struct View2: View {
    @State var text: String

    init(_ text: String) {
        self.text = text
        print("init View2  \(self.text)")
    }

    var body: some View {
        VStack {
            Button("Click") {
                print("Click view2 button")
            }
            Text("view2 text : \(text)")
        }
    }
}